Egg carton



Feb. 7, 1961 H. H. HEATH 2,970,734

EGG CARTON Filed Aug. 4, 1958 INVENTOR. HILLlS H. HEATH BY BUCKHORN,CHEATHAM 8BLORE ATTOFPNEKF United States Patent EGG CARTON Hillis H. Heath,1232 SW. Jefierson St., Portland 1, Greg. Filed Aug. 4, 1958, Ser. No.752,839

1 Claim. (Cl. 2292.5)

This invention relates to egg cartons and particularly to egg cartonsformed of molded pulp fiber.

It is a main object of the present invention to provide an egg cartonwith a simple latching or locking means to hold the cover portion of thecarton in closed relation to the base portion.

A further object of the invention is to provide an egg carton of thetype just described in which the latching or locking means includes apair of lugs on one portion which automatically enter openings on theother portion upon closure of the cover portion with respect to the baseportion.

A still further object of the invention is to provide such a cartonhaving a protruding lip on the base portion precluding the carton beingpicked up grasping the front edge of the cover portion.

Another object of the invention is to provide a carton in which the lugopenings are formed to resist withdrawal of the latching lugs from theopenings.

Various other objects of the invention will be apparent from thefollowing description taken in connection with the accompanying drawingswherein:

Fig. l is a front elevational view of a molded pulp fiber carton of thepresent invention showing the same in its closed condition;

Fig. 2 is a transverse section taken along lines 2-2 of Fig. l, on ascale larger than that employed in Fig. i;

Fig. 3 is a view similar to Fig. 2, but showing the car-- ton in itsopened condition;

Fig. 4 is a fragmentary plan view taken in the direction of the arrows44 in Fig. 3 showing a latch lug opening; and

Fig. 5 is a fragmentary plan view taken in the direction of the arrows5'5 in Fig. 2.

Referring particularly to Figs. 1, 2 and 3, the egg carton shown is ofmolded pulp fiber construction and includes a base portion indicated bythe general reference numeral 11 and a cover portion indicated by thegeneral reference numeral 13 integrally connected along one pair oflongitudinal edges by a hinge portion 15. The base portion is molded toprovide a plurality of essentially separate pockets 17, the interiorportions of which are roughly circular in cross section at the upperportions thereof and merge into square cross-sectional portions at thelower portions thereof. This construction leaves a series of triangularlands 19 as shown in Fig. 4 at the front lower margin of the baseportion, a similar set of lands 21 at the rear margin of the baseportion and a plurality of central lands 23 distributed along the lengthof the base portion. The front margin provides a short, upwardlyprojecting lip 25 for a purpose to be described presently.

In the particular carton shown, the walls between longitudinallyadjacent pockets are recessed downwardly at 27, as shown in Figs. 2 and3, for reasons not necessary to explain.

The cover portion 13 is of generally hollow form hav- .Patented Feb. 7,1961 ing a-rear wall 31, a top wall 33, a front wall 35 and end walls37. The front and rear walls are molded of undulated form to provideconcave parts 39 as shown in ice Figs. '1 and 5 and convex portions 41,the latter being in transverse register with'the pockets of the baseportion. This construction provides horizontal lands 43 at the frontmargin of the cover portion and similar lands 45 at the rear margin.

The front margin of the cover portion has an upwardly projecting lip 47which is disposed next to and in nesting relation with respect to thelip 25 in the closed condition of the carton.

Formed in the cover portion during the molding process is a pair ofdepending hollow lugs 51 which extend in a direction at right angles tothe plane between the base portion and the cover portion in the closedposition of the carton. It is thus apparent that the direction ofextension of a lug is also at right angles to a radius extending throughthe hinge axis of the cover and also extending through the lug.

Formed in each of the two lands 19 in register with the associated lug51 is an opening 55. The margins around each opening are inclineddownwardly, to'provide latching edges 57. The opening defined by theedges is slightly smaller than the cross-sectional dimensions of thelugs so that the edges are compressed slightly outwardly when the lug ispressed into the opening. The

edges thus resist withdrawal of the lug from the opening because thecorners of the edges bite into the side walls of the lugs. Thisresistance is enough to enable a filled carton to be lifted by graspingthe cover portion 13 only. However, the lip 25 is made to extendupwardly further than the lip 47 to encourage lifting of the carton bygrasping the base portion, and to prevent lifting of the carton bygrasping the lip 47. The hidden lip 47 does, however provide aconvenient means by which the cover portion may be opened by pulling upon the lip.

Preferably each lug 51 is slightly tapered from top to bottom tofacilitate its ready entry into the associated opening. This taper isnot sufiicient to interfere with the latching qualities of the edges 57on the sides of the lugs.

It is pointed out that the openings are the same distance from the hingeaxis as the lugs so that the lugs automatically enter the openings whenthe cover portion is closed.

It is further pointed out that the present invention has provided alatch arrangement that may readily be formed in the molding processduring the formation of the carton from pulp fibers.

Having described the invention in what is considered to be the preferredembodiment thereof, it is desired that it be understood that theinvention is not to be limited other than by the provisions of thefollowing claim.

I claim:

A molded pulp fiber egg carton having a body section for holding aplurality of eggs and a cover section hinged at one of its edges to anedge of the body section and movable to and from a position covering theeggs in the body section, the edge portions of said body and coversections remote from the mentioned edges being contiguous when saidcover section is closed, one of said edge portions having a lugprojecting in a direction which is generally at right angles to theplane between the meeting edges of said body section and cover sectionin the closed position of the cover section, the other of thejust-mentioned edge portions being formed with an opening to receivesaid lug, the margins defining said opening being inclined downwardly toprovide inwardly projecting corners to engage said lug, saidopeningbeing of a size slightly smaller than the lug so that the lug fitssnugly into the opening to slightly expand the opening in a down wardlyand outwardly direction so that the mentioned corners bite into thesides of the lug to retain the lug against accidental withdrawal, saidcover section having an upwardly extending lip remote from the hingebetween the body and cover section to enable the cover section to bereadily opened by grasping said lip and pulling upwardly, the bodysection also having a lip remote from said hinge and extending upwardlybeyond the cover lip References Cited in the file of this patent UNITEDSTATES PATENTS Randall Dec. 18, 1951 Frankenstein Sept. 7, 1954 FridayFeb. 10, 1959 FOREIGN PATENTS Great Britain Feb. 28, 1949 Germany Feb.27, 1958

